I've seen something on the web about removing the rear group from a 50mm prime to make a soft focus lens.
Simple enough to do (& reversible) so I tried it with one of my spares. The modified lens has a focal length about twice the originals so has to be mounted via bellows or similar to get focus, but with that results were quite acceptable. A lovely glow wide open which reduces fairly rapidly as the lens is stopped down.
I suspect stopped down half a stop would be good for portraits, but in 4 years have never got round to trying them.

Here are some pictures I took with a modified Olympus 28mm. I removed a glass inside and turned a rear glass the other way. The pictures are not very sharp, but from the center and to the edges they get a very diffuse and strange effect.
It works best on close up photos.

On which format was the midge image shot and was it cropped?_________________Dedicated to using manual focus lenses with digital. Equiped for photography from macro to panoramic & from ultra-wide to extreme telephoto. Mostly shooting outdoor macro. Experienced entomological taxonomist.